ARP Bolts World-leading Fastener Technology ARP started applying technology to race fastener design and manufacturing in 1968. We'll discuss five components of fastener technology in detail. Design Today's critical diesel fasteners - head studs and bolts, main studs and bolts, and driveline - have been designed stronger than ever before to handle the extreme loads. As a results, installation pre-loads - the amount the fastener is stretched during installation - are very high. Cometic Multi Layer Steel (MLS) Head Gasket Provide maximum sealing performance for today`s high output engines and require no sealants Ideal for aluminum heads to aluminum blocks and aluminum heads to cast iron blocks withstanding the shearing force created by the two materials. No need to re-torque, the embossing design of the MLS gasket promotes an even clamp load across the sealing surface allowing for measurable reduced bore distortion Cometic MLS Gaskets are comprized of multiple layers of stainless steel due to it`s increased strength, ability to rebound and resistance to corrosion. The outer layers of the gaskets are embossed and coated on both sides with Viton - a flouroelastomer rubber based material that is heat resistant to 250°C /482ºF. Viton is designed to meet the demands of a variety of harsh sealing environments, load conditions, and surface finishes. The center or shim layer is uncoated stainless steel layer which can be varied to accommodate multiple thickness requirements.